[Dovecot] rc31 -> "deferring operation: binding"

[Ben Beuchler]

> Well, I've really no idea. I know it works for many people and I
> couldn't get it to break when stress testing with hundreds of
> connections per second.

More info:

In the 5 minutes between when Nagios flagged IMAP as down (and we
tested it as down) until we restarted Dovecot, 103 authentications
successfully completed.  For the sake of reference, in the previous 5
minutes 311 IMAP logins succeeded.

Also interesting:  IMAP has died twice so far today (both times were
at typical daily usage peaks).  POP3 has not tested as down once.
Admittedly, we do roughly 9 X as many IMAP logins as POP, but they
both auth via dovecot-auth, right?

-Ben